Indicating crystal for timepieces



March 17, 1931. w [3, HAWLEY 1,796,652

INDICATING CRYSTAL FOR TIMEPIECES Filed Sept. 2. 1927 lNVENTOR W V aimzfZ M ATTORNEYS Patented Mar. 17, 1931 UNITED STATES WILLIAM D. HAWLEY, F SYRACUSE, NEW YORK INDICATING CRYSTAL FOR. TIMEIEIECES Application filed September This invention relates to clocks, watches and other time pieces and has for its object a. particularly simple and efficient adjustable indicating crystal by which the elapsed time can be readily indicated or by which both ings in which like characters represent corl5 responding parts in all the views.

Fig. 1 is an enlarged plan view of a watch provided with my invention.

, Fig. 2 is a fragmentary sectional view of the device taken on the line 22 of Figure 1.

Fig. 3 is an enlarged fragmentary detail view of the device shown in Fig. 1.

Fig. 4. is a fragmentary view illustrating he fluted margin of the rotatable crystal shown in Figs. 2 and 3.

Fig. 5 is a fragmentary detail view of a modified form of the crystal.

This invention comprises a. time piece having a rotatable crystal consisting of inner and outer layers in surface contact with each other, the outer layer being provided with graduations and is rotatable on the inner layer into a predetermined position to the time graduations on the face of the time piece.

1 designates the time piece including the usual case.

2 designates the bezel ring which holds the crystal.

3 designates the inner layer of the crystal, which is usually lass.

4 designates t e outer layer rotatably mounted on the inner layer 3.

5 designates a circle of. graduations on the outer layer and arranged concentric with the crystal. The layer 4 1s celluloid or some other material. Celluloid can be readily providedlwith raduations or indications while it is difiicuTt and expensive to provide graduations or indications on glass crystal 2, 1927. Serial No. 217,109.

because of the liability of glass crystals breaking. 1

It is impractical to stencil, sand blast, etch, or print on glass crystals. It is also impractical to use molded glass crystals with. 5:, graduations thereon as the molded glass crystals with the indications thereon would be prohibitively thick. Celluloid crystals alone detract from the appearance of the time piece or watch. provided with more than one circle of time graduations or indications as an inner circle 6.

The outer circle 5 is graduated into hours and fractions thereof indicating tenths of an hour, that is, periods of 6 minutes and coacts with the hour hand of the timepiece. The inner circle 6 is graduated into minutes and coacts with the minute hand of the time piece.

Assuming that it is desired to time an event which begins at nine oclock, the outer layer of the crystal is turned until the zero graduations on the crystal are in line with the nine oclock graduations on the face of the timepiece. The hands of the clock, of course, indicate nine oclock.

In Fig. 1, the position of the hands indicates when the event was completed. Taking the reading on the hour hand. circle 5, which is divided into graduations representing tenths of hours or intervals of six minutes, the reading is two and one tenth hours, or two hours six minutes. For long periods, the crystal is set with the Zero graduations inv line with the hour hand and the reading taken from the outer circle For short periods which take less than one hour, the zero graduations are set in line with the minute hand and the reading taken from the minute or inner circle 6.

In Fig. 1, the reading on the minute circle 6 shows elapsed time of twenty-two minutes of an eventstarted when the minute hand was at a quarter to nine oclock.

In Figs. 1, 2 and 3, the inner glass layer 3 is fixedly mounted in a bezel ring 2 and the outerlayer 4 rotatably mounted on the glass layer 3, with its margins extending into a channel or rabbet 8 in a metal ring 9 which The crystal may be mis fastened preferably by an adhesive to the margin of the glass layer 3.

In order to hold the layer 4 in its adjusted position, the margin thereof in the rabbet may be fluted as shown in Fig. 4; Also, to

facilitate the turning of the outer layer 4:,

said layer is provided, with. a boss or finger engaging portion 101 As the ring 9 mightcover the minute graduations on the face of the time piece, minute graduations 11 are provided on the ring 91 v In Fig. 5, the outer layer 4a is rotatably mounted on the inner layer 3w by having its margin 12 bent around the edge of the inner layer 3a. In this construction, the glass layer 3a ismade alittle smallerin diametei than usual to fit the bezel ring 7m and the bent over margin 12 of the outer layer 6 extendsinto the grooveii-i-v the bezel ring so that the entire, crystal fits. the bezel ring sufficiently tohold the crystal inposition and permit rotation of the'outer layer 40:.

In this construction, it is immaterial Whether or not the inner layer also rotates when the outer layer is rotated.

Bymy invention, any Watch or clock can be readily provided; with an indicating crystal for indicating elapsed time periods, standard and daylight saving, time, etc.

What I claim is:

In a timepiece having crystals including inner and outer layers and a bezel-1'ing,the outer layer being rotatable and provided with indicating characters and the inner layer being mounted in the bezel ring of the timepiece and aring fixed on. the inner layer and having a rabbet for receiving them-argin of the outer layer.

In testimony whereof, I have hereunto signed my name at Syracuse, in the county of Onondaga and State of' New York, this 31st day of August, 1927.. 1

WILLIAM D.- HAWLEY. 

